Gunnel Nyman Huntu GN 17

Please see below pictures for two Huntu vases.

The first is as I normally see them, with the bubbles clearly separated from the colour. In the second though the bubbles are sitting on the colour, there's no clear layer in between.

It could simply be natural variation in manufacture, although all the other similar bits I've had, both round vases and tall vases have had the bubbles and colour clearly separated, or possibly a piece of Humppila that has been re-signed ? both have the same Nyman acid pen signature.

Does anyone have similar bits that they could check and let me know their thoughts ?

Cheers

Gareth